Regulator for heating apparatus, etc.



July 30,' 1935. s. F. MACHLET REGULATOR FOR HEATING APPARATUS, ETC

Filed May 31, 1935 3 Sheets-Sheet 1 v July 30,1936.- G. F. MACHLET 2,009,697

REGULATOR FOR HEATING APPARATUS, ETC

- Filed May 31, 19:53 's sneets-sneet 2 GALVAHOMETER -1.;

'RECORBIHG Afro/hey.

July v1935- G. F. MACHLET 2,009,697

REGULATOR FOR HEATING APPARATUS, ETC

F iled May- 51. 195:5 :s Sheets-Sheet 5 HESTDN CELL mar;

Patented July 30, 1935 George FjMachlet, Elizabeth, N. J.

Application May 31; 1933, Serial No. 673,689

14 Claims.

This invention relates to regulators of the class disclosed in Patent No. 1,068,065 granted to me July 22, 1913, for efiecting heat-regulation of furnaces and'other purposes. The invention may 5 be employed where delicate regulation or control is desired.

In said patent, an element was introduced into a furnace, and connected to a galvanometer, whereby the electric current generated by the heat in the element was caused to move the needle of the galvanometer, to indicate upon a scale the heat of the furnace; and when the heat reached the desired point, an automatic device co-operated with the galvanometer-needle to diminish the supply of fuel to the furnace. If the heat of the furnace was lowered too far, the automatic device operated to increase the supply of fuel. Thus the heat was maintained w thin substantially the desired limits, with provision for adjustment of the regulator.

Gbjects of the present invention are to simplify the construction and operation and also reduce the cost of the regulating mechanism with which the galvanometer-needleco-operates, and also to obtain a more delicate regulation.

In said patent, the flow of fuel-gas into the furnace was controlled by a valve. The fuel consisted of gas inixed'with air'supplied under pressure. The valve itself was controlled by the automatic mechanism, which depended upon the needie of the galvanometer.

In practicing the present invention, said valve is operated by variable air pressure under contrai er the galvanometer-needle. To obtain this result, the fuel-controlling valve is operated by a piston or a diaphragm, which is mounted in an air-chamber. To this chamber air is admitunder pressure, thereby lifting the diaphragm or piston, and opening the valve to admit more fuel to the furnace.

For the use or the regulator, the necessary supply of air under pressure may be obtained by simply connecting the regulator to the source of compressed air from which the furnace itself is being fed. In one form of the invention, this supply of compressed air is tapped, and a nozzle is attached, from which a jet of compressed air the air-chamber may be raised or lowered, under the control of said needle. This is accomplished by mounting a bailie in the path of the jet of air that streams from the nozzle. This baflie may be in form of a vane, which is presented edgewise to the jet and therefore oifers little or no hindrama to the stream of escaping air, so that the pressure may raise and maintain the furnacefeeding valves open. The vane may swing to maintain the pressure upon the under side of the diaphragm in the air-chamber at any desired point, due to the greater or less deflecting control exercised by the vane or blade upon the constantly flowing jet.

One of the advantages of this regulatable current of air, is that such a vane, delicately mounted, so as to be movable without perceptible friction, may be operated by a connection made directly from the galvanometer-needle to the regulating vane, so that any movement of the needle will cause a movement of the vane, and so vary' abled to positively and delicately control the v0- luminous flow of compressed air mixed with fuelgas into the furnace. The diaphragm is self-returning, and drops in response to the deflection of the air-jet effected by the swinging of the vane.

Another feature of the invention is the adjustment whereby the automatic operation or control of the fuel-supply valve may be set to occur at any desired point in the path of the needle. The adjustable portion of the mechanism is made to he rotatable co-axially with the needle of the galvanometer, so that the efiect of the needle upon the regulator will be the same at all adjustments or" the regulator.

Qther features and advantages will hereinafter appear.

In the accompanying drawings,

Figure 1 is a sectional diagrammatic elevation showing the present improvements in regulating the heat of a furnace, the valve being shown in slightly open position. In this and other views,

some fragments or parts are shown in exaggerated proportion for clearness.

Figure 2 is a sectional elevation showing details of the galvanometer adjustment for prede- Cir '23 and the furnace 28.

termining the point at which the heat is to be automatically maintained.

Figure 3 is a part-sectional plan showing a furnace-element connected in a circuit having two branches, one branch having a recording galvanometer, and the other branch having a regulator for the supply of fuel flowing to the furnace.

Figure 3a is a sectional elevation showing the bafiie formed directly upon the staff of the galvanometer-coil and interposed edgewise to the path of the jet of air entering the chamber containing the bell or diaphragm, for regulating the air pressure therein, and thereby raising the diaphragm or permitting it to drop.

Figure 4 shows a sensitive or weak furnaceelement, which is connected to control a photoelectric relay, the latter being connected to operate the heat-regulating deflector blade.

Figure 5 is an elevation showing the photoelectric arrangement shown of Figure 4.

In Figures 6 and 9, the parts 46, 54 are omitted, and the compressed air-jet constitutes the only source of supply of air to raise the bell or diaphragm.

Figures '7 and 8 show different positions of the galvanometer controlled bafiie, and different effects produced thereby in obstructing more or less the jet of compressed air which flows into the leak in the bell-chamber, to raise the airpressure therein, and thereby open the fuel-valve.

The furnace whose heat is to beregulated, indicated at 20, is usually provided with Bunsen burners 2| supplied from a main 22 through which flows mixed air and gas under pressure, from a carbureter or mixer 23 of the Venturi type. The air is supplied to the mixer under pressure through a pipe 24, and the fuel-gas is drawn into the mixer from a supply 25.

The flow of compressed air through the furnacesupply pipe 24 is regulated by a balanced valve that rises and falls within a head 26. There is pressure mounted in said head a central upright valve-stem 21 provided with upper and lower valves 28, 29 to open and close upper and lower horizontal ports 3|], 3| provided in a cylindrical chest 32. Said ports are formed in partitions which divide the chest into top and bottom chambers separated by a middle chamber. Compressed air, under the control of a hand-valve 33, enters through a pipe 34 into the middle chamber 35 of the valve-chest and passes through the upper and lower ports 38 and 3|. The rate of flow depends upon the extent to which the valves 28, 29 are opened. From the upper and lower chambers the compressed air flows through outletports 36, 31 into pipe 24 on its way to the mixer It is only necessary to regulate the air-supply in order to control the heat of the furnace, because the air in passing through the mixer 23 will pick up a suitable proportion of fuel.

The automatic heat-regulator includes an ele ment 38 inserted in the furnace and forming part of an electric circuit 39. Also included in said circuit is a galvanometer 40, having a needle 4| fixed upon spindle 42, pivoted for the usual movements and carrying the usual coil 43. The needle 4| co-operates with a scale 44 to indicate the heat of the furnace. This galvanometer controls the extent to which the air-feeding ports 30 and 3| are opened by the valves; and the novel means whereby this result is accomplished forms one of the main features of the present i'nvention, which is useful for various regulating purposes besides controlling furnace-heat.

A weak electric current flowing through the element circuit 39 is made to control the opening and closing of the compressed air valve 28, 29, through the operation of the galvanometer-needle 4|; the invention being effective for this purpose without incurring the necessity of placing an obstacle in the path of the delicate needle, or appreciably checking its progress when impelled by the weak electric current.

The regulatable-power for raising the valve 28, 29 is illustrated as being derived from compressed air in the supply-main 34, from which a branch pipe 45 extends down to a conduit 46, which leads into a pocket 41, in which pressure of air received from 46 may consequently be maintained; and from this pocket extends a lead 48 that opens at 49 beneath an air elevated and supported bell 50, that is movable up in the head 26 (the latter having an air-vent 5|), accordingly as the pressure in 41 is raised. Reduction of airpressure beneath the bell, permits it to drop. The bell is sealed by means of a mercury seal 52, the mercury occupying the lower part of an annular space 53 within the head 26, surrounding the chest 32. The compressed air rising through the lead 48, fiows in beneath the bell, and lifts the same, thereby raising the valve-stem 21 and the valves 28, 29 thereon, thus opening the ports for the passage of a volume of compressed air from the main 34 to the mixer 23 and the furnace. The movements or positions of the self-returning bell depend upon the fluctuation of air-presssure which in this way may be maintained under the bell. If the pressure in the pocket 41 varies up 'or down, then the valves 28, 29 are opened or closed, and thus the supply of air and fuel to the furnace is controlled, whereby the heat of the furnace may be regulated.

The pressure in the pocket 41 may in some instances be manually regulated by a valve 5 3, Figure 1, to suit different kinds or conditions of work. The pressure of air in said pocket 41 and pipe 48, and hence in the bell-raising chamber 55, is also placed under automatic control. There is employed a pneumatic device controlled by the galvanometer-needle 4| in the circuit 39.

The pneumatic portion of the automatic controller may include a branch 59 extending from supply-pipe 45, and terminating in the form of a nozzle 51, having a small orifice and discharging a jet into a larger orifice 58 of a reversed nozzle 59. The latter may contain the pressure pocket 41, which isshown as forming the end of lead 48.

If the pressure in the pocket 41 is lowered by manual valve 54, it will reach a point that is less than the full-pressure discharge from the nozzle 51 (which is placed directly opposite the reversed nozzle 59 and in line therewith so as to give it efficiency in discharging the jet into the same). down through 45 and branch 56 and nozzle 51, and into, the variable pressure pocket 41, in which the air may be static, but capable of being increased in pressure by means of the jet from nozzle 51, to raise the hell 5!! and the furnace controlling valves28, 29; the lowering of airpressure in the pocket 41 permitting the self-returning bell to drop.

The valve 54 may stand open or closed, or at some intermediate point. If it is closed, then the pressure of the air in the pocket 41 will depend The air therefore from main 34 will flow entirely upon the force of the jetof air dischargreversed nomle or leak 59. When the pressure in the pocket .41 has reached a maximum, then the excess air received from nozzle 51 will be dissipated into the atmosphere. The pressure in the air-supply 45 is usually maintained at a constant point.

The force of the jet from 51 is controllable by the aforesaid galvanometer-needle; and a feature of the present invention is the provision for' co-operation, with the discharge-nozzle 51, of a current-deflector in the form of a needle-controlled blade 64 that maybe disposed midway between the nozzles and in linewith their discharge and intake openings. This blade is presented edgewise tothe stream of air and is mounted to swing on a pivot 6|, the axis of the pivot intersecting the axis of the jet and being longitudinal of the blade, which may have the form of a vane or feather. The pivot of the deflector, which is at right anglesto the air-jet, is provided with a crank-arm 62, so that the deflector may be swung. When parallel with the jet, the blade causes-a minimum of interference to the flow of air from the active nozzle, so that maximum pressure is produced in the static pocket or chamber 41, and. the bell 50 is raised to its highest point, and the furnace-supply ports 28, 29 opened to their fullest extent.

By swinging the crank-arm 62, the blade 60 may be turned to deflect the stream from the jet 51 away from the intake 58, so that pressure in the static chamber 41 falls to the minimum pressure, which minimum may if desired be determined or regulated by manipulation of the manual valve 54. The self-returning bell 50 will dropgradually in proportion to the slowly falling supporting air-pressure, and the furnace-supply valves 28, 29 will correspondingly close, so that the heat of the furnace will be reduced. Said arm 62, it will be understood, needs to be swung only a trifle and may be operated with no appreciable effort, and hence may be geared directly to the needle M of the galvanometer, as at Figure 2, or it may be connected by means of a link of silk thread t3, Figure 1, this being flexible and allowing considerable idle movement of the galvanometer-needle between the zero point and the zone where regulation of the furnace begins. This idle movement of the needle occurs while the furnace is warming up, and while the full pressure of air below the bell is being maintained.

It is a function of the galvanozneter ill to turn the blade 5d very slightly indeed to a position which, by the described methods, will cause the correct amount of fuel to be fed to the furnace to assure a constant specific temperature. The blade at, being mounted in the jewels 85, is so, easily turned, that the slight amount of energy available from the galvanometer W is more than sufficient properly to operate it. The resistance offered to the moving galvanometer-coil 53 is indeed so small that the error created by it is hardly discernible, and in most cases may be neglected. It is therefore practicable to control furnace-temperature (for example) by means of an indicating galvanometer to which this device has been added.

The problem of actuating the governing blade M by means of the galvanometer may be solved as at Figure 2, which represents one of many methods that may be employed. The blade-actuating arm 62 moves in a plane perpendicular to that described-by the needle (or the needle-extension 6?) of the galvanometer. slack thread is employed as link 63.- The opera-.

A thin silk tion of the various units as well as their specific function in the controlling device, may now be readily understood and followed. The galvanometer, by means of the thermo-couple inserted in the furnace, indicates the temperature in the furnace, which, for example, should be kept at 1500 degrees Fahrenheit.

While the deflector is presented at an angle of a few degrees to the path of the airjet from-the nozzle 51, the air streaming from said nozzle is directed to one side of 58, and therefore may not overcome the current of air of lower pressure, which therefore vents from the reverse nozzle 59. However, if the baille-blade takes a position substantially parallel with the nozzle 51, as in Figure 8, the resistance of the baflle to the-stream of highpressure air becomes negligible. The force of the jet of air from the nozzle 51 checks the air venting from the reverse nozzle 59, and eventually overcomes the primary pressure in 59 and forces its way into said nozzle, as indicated by arrows in Figure '1, and serves to raise the pressure in the bell-lifting chamber, and to raise the bell and valves 28, 29. It will be understood that the force of the jet from 51 proportionally increases as the blade is swung toward its horizontal position (Figure '1), so that the pressure in the airpocket 41 correspondingly increases.

It has been seen that this varying pressure caused by the turning of the blade 54 is utilized for raising the furnace-feed valve 28, 29. The amount of air passed through the mixer 23 is governed by the positionof valve 28, 29, and, by

reason of the Venturi arrangement in the mixer 23, the supply of fuel-gas picked up by the airwill vary proportionally, as will be understood by those skilled in the art.

In Figures 6 and 9 the leftward directed arrows indicate the passage of air from jet 51 when the valve 54 is entirely closed, or when the pipe 46 is omitted, which may be done in some cases. Venting is not maintained from the reverse nozzle ,or leak 66, in which the air is originally at pressure in 86. may vent (see arrows at Figure 6), and decline to atmospheric pressure.

From the foregoing it will be sen that the movements oi the galvanometer-needle are communicated to the deflector, and the changes in the position of the baiiie cause variations in the pressure in the bell-chamber 25, due to greater or less dissipation of the air discharged through the nozzle .51, and the bell is raised or self lower ed accordingly, thereby increasing or reducing the flow of air and fuel to the furnace.

If the regulation of the furnace in some cases should admit of the nozzle 5?, 55 being of equal diameters, relatively low primary pressure in the chamber 51 could be secured by means of the manual valve 55, However, in the preferred prac fourths of the diameter of the receiving orifice or leak.

The nozzle 57 of course'delivers air at higher pressure than the primary pressure which prevails in the receiving nozzle 59. For example,

the pressure in 51 might be fourteen inches of water-column, while the pressure in nozzle 59 will be half as much.

Other valve operating means, such as flexible diaphragms, bellows, etc., may be employed.

The nozzles may be spaced apart approximately one quarter of one inch, and the width of the blade 64 may be about three thirty-seconds of an inch, say twice the diameter of the receiving orifice in the reverse nozzle 59.

It is a function of the galvanometer to turn the blade 64 to a position which will causethe fuel to be fed to the furnace at such a precise rate as to assure a constant temperature within the furnace, which is a desideratum for many classes of work. Said baffle 64 because of its jewels 65 is so easily turned that the slight energy available from the galvanometer is suflicient to operate the deflector. The resistance which the deflector offers is indeed so small that the error created by it is hardly perceptible and is negli-.

the turntable 68, fits upon the stud 69, so as to permit rotation of the turntable in either direction; and a thumb-screw H may fasten the turntable when the proper adjustment has been reached, Figures 1 and 2.

A pointer for aid in adjusting the head 68 about the stud 69, is indicated at 1|, in position to cooperate with scale 44.

After the described rotative adjustment has been made, the temperature of the furnace rises to the point of beginning the regulating operation at 1496 degrees. The heat of the furnace continues to rise, and the needle 4| turns the arm 62 and causes the blade 64 to stir from its horizontal or maximum position, and thereby cause the current of air from the Jet 57 to be deflected slightly, without opposing the swinging action of the blade thus permitting the pressure in 41, 46 to fall a little, thus lowering the air-pressure in the pipe 48 and the bell-supporting chamber 50, so that the self-returning bell descends a. little, and the balanced valves 28, 29 close a little, thereby diminishing the supply to the furnace of air mixed with fuel. A variation of but 6 degrees Fahrenheit may be suflicient to move the valves from extreme open to extreme closed positions. Hence the temperature of the furnace cannot rise above the desired 1504 degrees Fahrenheit, because at this temperature the fuelsuppiy is cut to its minimum.

It will be understood that as the temperature of the furnace rises above the lower limit 1496, the fuel-supply is smoothly and proportionally reduced little by little until no further rise of temperature occurs. It is noted that the reduction in temperature is not effected, step by step, but gradually, without irregularity, and there is absence of jerky motions.

A slight drop in temperature of the furnace will cause a retraction of the galvanometer-needle and bring about an immediate proportional rise in the amount of mixed air and fuel flowing into the furnace.

raise or lower its temperature.

It is evident therefore that after a short time of wavering, a position of the indicating needle will be found, or said needle will come to rest at such a point that will cause the exact volume of fuel to be fed to the furnace that will neither This position must correspond to a temperature which lies at some point between 1496 and 1504 degrees Fahrenheit in this illustration, since at 1496 the maximum amount of fuel is delivered to the furnace, thereby causing a rise in temperature, while at 1504 the minimum fuel is supplied, thereby causing a fall in temperature.

Since 1500 is midway between said two limits,

it may be assumed that this signifies the temperature at which the furnace will be maintained. It is of course possible that this temperature may fluctuate one degree above or below the exact point desired, but this minute inaccuracy may be entirely disregarded for all practical purposes. In practice, it is found that after the temperature has reached the desired point, the graph that is produced by the galvanometer-recorder will be in the form of a straight line for an indefinite time, inasmuch as the fluctuations of the galvanometer-needle are too slight to be perceptible. It is noticed that the water-column will rise and fall severalinches without any perceptible movement of the galvanometer-needle, thus illustrating the delicacy of the control effected by this invention over the furnace-heat.

At Figure 3a is shown,-in sectional elevation, a simple form of the invention in which the baflle is provided upon the staff of the galvanometerneedle 4l. Its coil is seen at 43, and the scale at 12. At Figure l, the usual staff 42 carries the coil 43, but at Figure 3a the staff is marked 73, and it is formed at its upper end with extension 14, this portion being flattened to form a deflector-blade 15 corresponding with 64; the needle-staff being mounted in upper and lower pivot-screws 16, ll, in supporting bracket 11. The deflector l5 occupies a position between the nozzle 57 and the leak or reverse nozzle 58, as at Figure 1. The adjustment for a given degree of heat may be controlled by the same means as are indicated at Figure 3, in which rheostat 84 is included in the galvanometer-circuit for the purpose.

Figure 3 shows a sectional plan of one form of apparatus, in which is included in the furnace circuit a recording galvanometer of standard construction. There is also included in the same circuit the deflector 15, which is. formed upon the staff of the galvanometer-coil 43, as in Figure 3a. At Figure 3 the main portion of the needle may be cut off, as indicated in dotted lines. By cutting off this portion a considerable reduction is effected in weight, and hence the tendency of the needle to overthrow or vibrate is minimized or overcome. The portion of the needle which is retained is indicated at 18; and there is also shown the same extension-arm 19 as in other views, tending to balance the needle.

At Figure 3, electrical circuit includes the element 38 and leads 80, 8| connected to a recording galvanometer 82. From the lead 8| extends a wire 83 to connect with coil 43. Between the latter and the lead is included a rheostat 84, by the use of which the temperature may be set or indicated at which it is desired to maintain or control the heat of the furnace: this taking the place of the rotary adjustment at 59, 10,11, Figure 2.

In starting the furnace according to Figure 3,

the rheostat may be set to offer amaximum of resistance temporarily, so that the coil 48 cannot be turned by the electrical current generated by the heating of the furnace. During such heating, the needle-members I8, I9 may be temporarily set manually-to a position in which the deflector I5 is presented edg'ewise to and parallel with the current of air from the jet, as at Figures 4 and 8. The operator may watch the galvanometer 82, and as soon as the furnace isnearly hot enough, he may readjust the rheostat 86 sufliciently to cause the coil and current-deflector to co-operate automatically in the manner already explained, without further attention. The rheostat 84' is adjusted until it permits just enough electric cur-.

rent to flow through the coil to maintain the blade in a slightly diverting working position, thereby keeping the pressure in the bell-chamber up to the point atwhich'just. sufficient fuel will be steadily fed to the furnace. The rheostat 84 thus permits manual regulation of the furnace-heat.

Figures 4 and 5 show provision for using an extremely sensitive galvanometer, one that is too weak to operate the deflector 84. The weak galvanometer is made to control a delicate relay, and the relay has power to operate the deflector. The sensitive galvanometer is indicated at 85 as being connected to the element 88 (or to other source of power) by a circuit 86 which includes the rheostat 84, settable to control the heat of the furnace. Galvanometer 85 includes a needle upon coil 43; this needle being broadened sufliciently at 81 so-that it can cover a lightslit 88 in a cover-plate 88 of Weston photoelectric cell 98.

The light from a bulb 8| shines through the slit 88, producing a degree of electromotive force far beyond what could be directly produced by the element 38 (or other weak source). When the furnace is warmed up, the needle 81 may cover the slit 88, thus causing a fluctuation in the electric current which flows through a circuit 92 togalvanometer 83. To the needle of the latter is attached the deflector 64, as explained in connection with Figure 3, this deflector controlling escape of air from the leak 58, or the supply of compressed air from 51, in order to control the heat of the furnace, as above set forth. It will be seen that this device can control variables which are measured by means of galvanometers or other instruments, which have still less available energy than that which is usually available from a good thermo-couple. The improvement may also be used in connection with a regulator or adjusting mechanism to be controlled by a magnetic compass, which of course has not enough energy to operate the which is approximately twice that which is produced by an electrothermic couple. This 'electromotive force is proportional to the amount of light that falls upon the photronic cell, through slit 88 in light-tight housing 88.

The broadened needle 81 moves in a plan which will enable it to cover-the slit, thereby shielding all light from the cell. The parts are so placed that when the furnace has reached the desired temperature, the broadened needle 81 will cover half of the slit 88. This tends to operate the deflector 64 in away. to diminish the supply of fuel to the furnace 20 (or to effect the desired control of other apparatus than furnaces). Since the indicator-needle 81 has only to intercept a beam of light, it is not retarded by so doing, or by moving the baflie 84.

The force of the electric current in the coil circuit 39, depends upon the degree of heat in the furnace, in the present illustration of the invention. Whether the invention is applied to this or to any other regulatable apparatus, it will be understood thatthe fluctuations which it is desired to regulate, whether in the heat or any other condition, are caused to vary the force of the current flowing through the coil 43, thereby actuating the' coil. It will further be seen that the movements of the coil so caused are communicated to the governor-vane 64, resulting in more or less direction of the air-jet from 51, with consequent lowering or raising of air pressure in the bell-chamber and depression or elevation of the bell. This is caused to effect regulation in the heat or other condition of the apthen be some degree of over-correction, which will cause another reverse shift of the baflle, and so on; but these baflie shifts are all selfcorrective, and with every movement the extent of shifting lessens, resembling the tendency of the vibrations of a pendulum to diminish and cease. The bailie-mechanism-maly be self-corrective to such an extent that eventually it may come to. rest at a point of equilibrium. The governor is therefore self-equilibrating, and is distinguished from regulators in which bounds are set to the vibration of a galvanometer-needle,

and in which an altering mechanism is brought automatically into action by reasonv of the conclusion of the needle stroke in each direction. In suchformer regulators, the heat or other condition was not brought to one point and caused to remain there, but the condition was caused to alter a little but repeatedly so long as the operation of the furnace or other apparatus was maintained. It was incessantly stepped up and stepped down; but by the present invention the deflector makes but a few self-limited shifts or vibrations before it reaches its point of equilibrium, where it remains without anything further, and no stepping mechanism is found to be necessaryf Variations may be resorted to within the soon I of .the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:

1. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an air-chamber,

means being provided for constantly supplying compressed air to said chamber to lift and support said bell, an electric circuit including ansaid jet and presented edgewise thereto, to vary its efliciency.

2. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a self-returning bell connected to said valve and enclosed in an air-chamber, said chamber having a vent above said bell, means being provided for supplying compressed air to said chamber but only below said bell, a galvanometer-circuit including an element in said furnace, a jet of compressed air flowing through a nozzle and into said chamber through an intake, and a deflector turned by means of said galvanometer and in the form of a blade interposed edgewise to and in the path of said jet, to deflect said jet clear of said intake.

3. The combination with a furnace and a heat-regulating valve to control the flow of mixed air and fuel to the furnace, of a diaphragm connected to said valve and enclosed in an aircharnber, an electric circuit including an element in said furnace and also including a galvanometer, means for directing a jet of air into said chamber to raise the air pressure therein sufficiently to operate said diaphragm, said galvanometer having a swingable deflecting blade presented edgewise to the jet, and an adjustable element being co-operative with said galvanometer for predetermining the point or zone of its effectiveness in regulating the flow of fuel to the furnace.

4. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an airchamber', means being provided for charging compressed air into said chamber, an electric circuit including an element in said furnace and also including a galvanometer, a governor operated by the galvanometer for varying the pressure of compressed air charged into said chamber, to effect corresponding closing and opening regulation of said valve, including a member carrying said governor and manually adjustable upon a fixed support about the axis of the galvanometer-needle, for predetermining the degree of furnace heat, and an index for indicating the extent of adjustment and having a' scale.

5. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an air-chamber and having a seal, means being provided for constantly supplying compressed air to said chamber to lift the bell and open the valve, a galvanometer-circuit including. an element .in said furnace, a jet of compressed air flowing through a leak into said chamber, and a baffle turned by means of said galvanometer and interposed in the path of said jet, to ofier varying resistance to the passage of the jet into the bell-chamber.

6. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an air-chamber and having a seal, means being provided for constantly supplying compressed air to said chamber to lift the bell and open the valve, a galvanometer-circuit including an element in said furnace, a jet of compressed air flowing through a leak into said chamber, and a bailie turned by means of said galvanometer and interposed in the path of said jet, to offer varying resistance to the passage of the jet into the bell-chamber, and

manually variable means to supply compressed air constantly to said chamber.

7. The combination with a furnaceand a heatregulating valve to control the flow of mixed air and fuel to the furnace, of a diaphragm connected to said valve and enclosed in an air-chamber, means to supply compressed air constantly to said chamber, a manually-controlled valve for controlling the supply of compressed air to said chamber, a galvanometer-circuit including an element in said furnace, and a governor operated by the galvanometer for automatically varying the pressure of air upon said diaphragm in said chamber, at all adjustments of said manual air-valve, to effect corresponding closing and opening regulation of said fuel-valve.

8. The combination with a furnace and a valve to control the flow of mixed air and fuel to the furnace, of a self-returning diaphragm connected to said valve and enclosed in an air-chamber having a leak below said diaphragm and a vent above the same, an electric circuit including an element in said furnace and also including a galvanometer having a needle, means for directing a single jet of air into said chamber through said leak, to raise the air-pressure sufficiently to lift said diaphragm, to effect opening movement of said valve, a deflector mounted in the path of said jet and presented edgewise to both said jet and said leak, and means to enable said needle to turn said deflector to direct said jet of air clear of said leak.

9. The combination with a furnace and a heatregulating valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an air-chamber, said chamber having a leak, means being provided for supplying compressed air to said chamber, a galvanometer-circuit including an element in said furnace, a jet of compressed air flowing through a nozzle and through said leak into said chamber, and a battle turned by means of said galvanometer and in the form of a blade interposed in the path of said jet, to offer varying resistance to the passage of the jet into the chamber, the diameter of nozzle through which the jet is discharged being substantially less than the diameter of the receiving orifice for said jet.

10. The combination with a furnace and a heat-regulating'valve to control the flow of compressed air and fuel to the furnace, of a bell connected to said valve and enclosed in an airchamber, flexible means being provided for charging compressed air into said chamber, a turntable upon which said charging means is mounted, an electric circuit including an element in said furnace and also including a galvanometer, and a governor upon said turntable and operated by the galvanometer for varying the pressure of compressed air charged into said chamber, to effect corresponding closing and opening regulation of said valve; said turntable being manually adjustable about the axis of the galvanometer-needle, for predetermining the degree of furnace heat.

.11. The combination with a furnace and a heat-regulating valve to control the flow of mixed air and fuel to the furnace, of a self-returning diaphragm or hell connected to said valve and enclosed in an air-chamber, an electric circuit including an element in said furnace and also including a coil, means for supplying a jet of air to raise said diaphragm, and an air-current defiector in the form of a blade presented edgewise to the jet and mounted upon the axis of said coil to turn therewith, tor varying the pressure of air upon only one side 0! said diaphragm in said chamber to eflect corresponding closing and opening regulation of said valve, said circuit also including a separate galvanometer for read= ins, and the coil having a rheostat iordeter mining the degree oi heat to be attained by the Iurnace.

12. The combination with afurnace and a heat-regulating valve to control the flow oi compressed air and iuei to the iurnaoe, of a di aphragm connected to said valve and enclosed in an air-chamber, means being provided for constantly supplying compressed air to said chamher to. lift the diaphragm and open the valve, a galvanometer-circuit including an element in said furnace, a relay operated by the galvanometer in said circuit, a jet ot compressed air flowing through a leak into said chamber, and a tolittthediaphrasmandopenthevalve,a-

gaivanometer-circuit including an element in said iurnace, a relay operated by the galvsnometer in said circuit, a jet of compressed air flowing through a leak into said chamber, and a Dame turned by means of said relay and interposed in the path of said jet, to alter varying resistance to the passage of the jet into the diaphragmchamber, said relay including a photo-electric cell having a light-slitted cover, said gaivanometer having a broad needle tor covering the light=slit in the cover.

14. A seli-equilibrating regulator including a by variations in the condition or the apparatus to be regulated, a self-returning diaphragm movable in response to fluctuations in air-pressure, an air-inlet leading to said diaphragm,

means for supplying acurrent 0! air through said inlet for producing pressure upon only one side 02 said diaphragm, a deflector presented edgewise to said current and swingsble to vary the direction of flow of the current sumciently to clear said inlet, said deflector shiitable by said coil, said diaphragm being responsive to variations in the air-pressure thereon due to swinging of said deflector, and means operated by said diaphragm to control the condition of the apparatus to be regulated.

.GEORGE RMACHLET. 

